Ca(100)表面芯态本征能位移的理论研究

用基于局域密度泛函近似的全电子线性缀加平面波（LAPW）薄膜方法计算了由7层面心立方Ca(100)原子面构成的系统的电子结构，给出了各类原子的Muffin-Tin(MT)球内不同轨道的价电子数、层投影价带态密度及3d、4s和4p带的重心位置。计算结果表明，表面原子的芯态本征能要比中心层原子的低0.56eV左右，可认为是表面层类s、类p电子外泄和表面原子3d带因配位数减少而窄化的共同结果。

Theoretical Study on the Surface Core-Level Eigen-Energy Shifts of Ca(100)

The first principles all-electron linearized augmented plane wave film method in the local density functional approximation is employed to investigate the electronic structure of the seven-layer Ca(100) slab system. The partial valence charges in muffin-tin spheres for various atom types, the layer projected local state densities of valence band, and the centroid shifts of 3d, 4s and 4p bands are given. The calculation shows that the core-level eigen-energies for surface atom are about 0.55 eV lower than those of central atom, which can be attributed to the contribution of both the spill-out of s, p-like valence charge to vacuum and the narrowed of surface atom 3d band originated from the reduction of coordinate.